Donor breast milk optimised for newborns

Donor breast milk is used to support pre-term and intensive care newborns. Image: iStockMEDICAL engineers and scientists from the Hartmann Human Lactation Research Group are seeking to improve the pasteurisation method for donor human milk, using a novel technique that will eliminate bacteria and optimise nutritional benefits.

Based at the University of Western Australia, the research aims to improve the quality of milk used to support pre-term and intensive care newborns.

Lead author and medical engineer Lukas Christen says currently thermal pasteurisation inactivates important bioactive components of the milk.

“It was the logical move to start the program with an engineer; someone with an understanding of physical methods and how we can build a new pasteuriser.”

After trialling methods using ultrasound, the group turned to UV-C radiation; a pasteurisation method which has previously been used in water, beer, wine and berry juices.

“In my work we are focusing on bile salt stimulated lipase [BSSL] because we know that we lose 100 per cent of the activity of this in the thermal treatment and that it’s an important enzyme as it allows the infant to absorb the fat in the milk,” Mr Christen says.

“We wanted to see if we could reduce the bacterial load and at the same time if we can increase the retention of BSSL compared with the current process.”

To overcome the limited penetration depth of the short-wavelength radiation, the group used a magnetic stirrer to move a UV-C lamp through samples of milk donated through the Perroon Rotary Express Milk Bank at King Edward Memorial Hospital.

“Safety is a big issue—it is so important that we make sure we don’t transfer any diseases from a donor to an infant,” he says.

Not only did they find that UV-C radiation method reduced bacterial content to within acceptable standards, but that even at highest tested dosage of radiation there was no reduction in active BSSL.

“Now we will look further at other bioactive components to see if they are damaged with the UV radiation,” he says.

“If we see that vitamins are more sensitive than proteins we can reduce the dosage to optimise the retention of vitamins while still retaining a sufficient reduction of the bacteria.

“With over a thousand different peptides, cytokines, vitamins and other components of human milk we are just in the beginning of the validation of a new pasteurisation method.”